This invention relates to pre-engineered buildings and in particular those pre-engineered buildings which are constructed of purlins having a lower horizontal member with a raised toe. This type of purlin includes popular Z-shaped purlin joist with the raised toe of the lower section of the Z-shape, and the C-shaped purlin again with the raised toe on the lower horizontal member. There are other joist cross-sectional shapes, but this invention is particularly suited for shapes having this configuration.
In the typical construction of these pre-engineered buildings, the purlins are used to construct the roof framing. A roof sheet, typically a sandwich panel of aluminum sheet around foam, fiber glass reinforced sheet or corrugated painted aluminum sheet is attached to the outside of the upper horizontal of the C or Z-shaped purlin joist. For some uses of buildings, it is satisfactory to leave the interior unfinished. However, in order to provide a finished interior ot to insulate the building sufficiently, it is necessary to support ceiling sheets such as accoustical panels, translucent lighting panels or insulation sheets such as glass fiber batting or like sheets between adjacent purlins. It has been suggested to provide sheets of metal between the purlins on which the ceiling sheet may rest. It was proposed to rest one end of the support on the top of the lower horizontal member of one purlin and provide a hook on the other end of the support to hook over the entire upraised toe of the next adjacent purlin.
This was found entirely unsatisfactory since a rigid body was required which was not easily installed without deforming the support. An original proposal was considered to hook over the upraised toe of the purlin which angled upwardly at an angle of about 45 degrees. However, following the shape upraised toe of the purline on the outside and returning the hook around the inside of the toe to prevent the support from falling off was difficult to install and required deformation of the support in order to get it into place.
Facing these problems, it is an object of this invention to provide a support to hold ceiling sheets across the roof of pre-engineered buildings constructed with purlins having a lower horizontal member with an upraised toe.
It is an additional object of this invention to provide a support which may be easily installed without deforming the support.
It is a further object of this invention to provide a support which by its shape will spring into place and hold on the upraised toe of the purlin without extending to the inside surface of that upraised toe.
It is an additional object of this invention to provide a support which combines reinforcement of the support with a shape to also provide the springing action in the support to hold it in place resting on top of one adjacent purlin and clipping underneath onto the toe of an adjacent purlin.